Field of Invention
The present disclosure relates to a separating fluid for separating multilayer systems, in particular in photovoltaic modules, batteries or screens, for the purpose of recycling.
The present invention refers to a method for separating multilayer systems, in particular in photovoltaic modules, for the purpose of recycling, comprising a wash with a separating fluid.
The present invention further to use of a separating fluid for separating multilayer systems, in particular photovoltaic modules, for the purpose of recycling.
Finally, the present disclosure relates to a facility carrying out the above method of the kind named above.
Brief Description of the Related Art
The increasing distribution of photovoltaic modules, electronic components and other objects present in multilayer systems increases the demand for suitable methods and materials for disposal and recycling of decommissioned multilayer systems and wastes arising from their production. Processing and recycling are targeted specifically at the production of secondary raw materials that can be returned to the economic cycle. Questions of environmental protection that are also against disposal of the decommissioned multilayer systems and waste without any processing are playing an increasing role as well. These conditions lead to the requirement that the recycling process in itself should be performed as far as possible in an environmentally friendly manner and compatible with recycling of material.
The methods and separating fluids currently in use are based on the application of chemical and thermal processes for silicon thick-film modules, such as crystalline silicon modules, on the one hand and mechanical and chemical separating processes for recycling of thin-film modules or CdTe-thin-film modules on the other hand.
Two types of photovoltaic modules are known. There are photovoltaic modules based on silicon wafers that are embedded within two glass panes by lamination of ethylenvinylacetate (EVA) and applied to a suitable frame, resulting in silicon-thick-film modules. The other type of photovoltaic cells or photovoltaic modules is produced with thin layers that are applied directly to the glass panes by physical vapor deposition and/or chemical vapor deposition methods. Different thin-film cell varieties are available on the market, such as amorphous silicon, microcrystalline silicon, cadmium telluride, copper indium diselenide and gallium arsenide.
The known methods for recycling the photovoltaic modules are based on a thermal separating process, i.e. the destruction of the EVA bond, in connection with chemical methods for cleaning the resulting silicon wafer or the raw silicon. The methods are energy-intensive and only suitable for thin-film modules within limitations.
Another known method is substantially based on sulfuric acid and hydrogen peroxide causing an etching process that leads to separation of the multilayer system. The disadvantage is that use of such substances is not environmentally compatible and separation and concentration of the recyclable materials after etching may be require elaborate methods.
Other prior art methods result in the entire dissolution of the materials, due to the acids used to remove layers. These other prior art methods require highly energy-consuming and material-consuming methods, such as electrolysis, to separate these dissolved materials from the etching solution used so that the waste materials are available for further use.